CATAPULTA Increasing Power Pt1 

And next episode: Joerg Sprave appears out of nowhere and mounts a magazine and a motor to that beast

mark the date !!!! tods wearing a shirt with no wholes in it

I think a great part of these machines would be considered now 'wear items'- the wood, sinew, some fittings and components just eventually crumble and crack under the forces of the torsion going through it. So like a modern artillery piece they'd probably have a period of time when the garrison or unit assigned to them goes over them and pulls a unit out if its tolerances started getting sketchy after being lugged around or left out in the rain and driven hard. Being the romans, they may have even had spare parts made up roughly to fit certain types of units and just do some fine fettling to suit the particular machine quicker, especially for things like the torsion components of arms, strings and ropes.

Hey Todd, I recently inherited my grandma's crossbow and bolts made in northern France in the early 20'th century. The bolts have the same geometry that you derscribe and I think it's to minimise friction at launch. The back end is made from bone and the head made out of horn is attached with a riveted lead ring. These low friction materials are the only two points of contact with the brass plated way on the crossbow. I'll try to get you some pictures sometime in the future if you're interested.

Accidentally a few years ago I got a book about the history of katapults ( a Hellenic complex word from kata=against and pelti = a kind of shield used by auxiliary light forces mainly in Thrace (North east Hellas). Now katapults were divided in 2 categories: Oxyveloi = from Velos= arrow and oxy = sharp pointy, and the ones that would throw round missiles, (stones mostly). Now the bibliography clearly shows that all types of katapults were invented and perfected by the Hellenes, since they were the ones that had the mathematicians and physicists that developed and applied theories on improving these machines by means of materials, design and constructions, but they also solved the ballistics trajectory problems, going to the extent of producing simple devices to practically compute trajectories on the field during battles. To mention only one of them Archimedes, I carry on by saying that the peak of the katapults of all kinds was the mechanics of the army of Alexander, which by the way used sinew for the torque, whose manufacturing and processing methods have been lost. The Romans simply copied and mass produced. After the fall of the ancient Hellenic world and the forced establishment of christian religion together with the banning of the study of mathematics physics and medicine with the punishment of death by the east Roman empire ( Byzantium), all this knowledge was lost, and that explains the ridiculous technology of the trebuchet, UNTIL renaissance when the Arabs that had preserved sciences brought back the vital math and physics so that similar levels of efficiency could be repeated.

I used to operate one of Lens first 3 span catapultae at Verulamium years ago. The support arm had a number of holes allowing the main body to be set at fixed angles.Putting out ranging markers made it very easy to consistently adjust for differing ranges.

When I was a young boyscout, some adult put one of these together and used it to lob golfballs. His tension bundles used short bungie cords stretched to their limits, and the bow arms were table legs with the backside profiled for the string to lie flat. I don't know what the draw was, but it took a pair of 8yo boys to draw back the winch. Lots of fun, we all thought it was the coolest thing.

Tod! The bolts of Dura Europos are not the only one ever found any more. In 2020 2 intact ballista bolts were discovered in Utrecht, the Netherlands, near one of the castella there. It did not have wooden vanes but traces of glue at the place where the fletchings would have been. So much more appropriate for Xanten-style catapultae. Both bolts were tapered, one more ponounced then the other. Look it up, it's a really nice find.

You know you'd made great content when I'm dreading seeing the progress bar reach the end. Amazing film, can't wait for pt2. Hope everyone is liking these as much as I am so we can keep getting similar stuff in the future.

Have you considered publishing a book on how to build all the medieval equipment you know how to build? It would be cool to know how to build a siege engine, crossbow, sword, armor, and etcetera...

I remember reading an article on Scientific America many years ago. The authors proposed an unconventional reconstruction of ballistae, in that the arms would pivot inward rather than outward. The reasoning was that the outward motion is actually restricted by the shape, it cannot extend forward, and this limits the amount of energy which can be transferred to the projectile. By their simulations the inward motion would allow a larger energy transfer, thus range and impact. Furthermore they noted that some of the remains and contemporary depictions have frames in which the torsion springs appear to be unnecessarily apart for the outward motion, but consistent with an inward motion (some of the pictures on the wiki page, especially of the lighter ones, are examples of these). Also, some of the reported ranges would not be achievable with the traditional configuration, whereas with the unconventional one... we can't still explain the animals of the Hercynian forest, which is why accounts don't count, I guess, and veterans telling stories about their wars, sure thing... Anyway, no idea if this reconstruction is historically plausible, and even if there were cases it is probably not applicable to all, but it is an interesting notion in itself.

aww yea, a ''slow TV'' ''Rant'' in depth about old war machines, today is a good day indeed

I bought both of those books a few years ago for a future build just like yours. I got them for about $40 each. It took me a few years to find the second book.

You just go on and on .. and we still be here!

Now here's me looking forward to part 2.

Thanks Tod. I love watching this. Best channel on RU-vid.

Daaaamn! You can´t leave it on a cliffhanger! Excellent video as usual.

I managed to get a copy of that book from my local library. absolutely stunning. I really liked reading all the little interpersonal salesmanship.

That was very brave standing there with an armed bow while drilling.

Wow so awesome wish I had you as a teacher in school

1:49 Well don't let me stop you! I'd happily watch 20, 30, 90+ minute film about every dimension, material and pattern an of ancient artillery piece 😁

This is a great video, and a great series on a rather overlooked weapon. I'm not normally one to support piracy, but even though this book is out of print, you can still find it on z-library for free. I'd always prefer to buy from the author, but for cases where that's not possible, it is certainly still possible to get the book.

This channel gets me tru my depression. Great job Tod

Was good to see you on tv today in scrap heap challenge....

"my lever is long, I can put a lot of power on it. Jenny can't hold it" *smirks*

Dammit Tod! That's another Sunday afternoon you've stolen from me! Your videos are so engaging, so interesting that once I start, I can't just put off watching it until later. It goes to show that when a presenter truly loves his subject, it's damn near impossible to be drawn in. Now, instead of doing the lawns like I really should, I HAVE to watch the next one, grumbling all the while of course.....s'not fair....s'not fair at all.....

Nice machine! I need to do an up-date on my giant inswinger ballista. Some of the specifications on it; 14 feet wide, 14 feet long, 14 feet tall, engines are 5.5 feet tall, 5 foot long limbs, +/- 45 tons of tension on each engine at full power with a 5 ton draw weight, at 101" powerstroke . It's huge, and weighs around 3500 pounds.

Giving tod a sub. Hes building all the toys i wish i had as a kid

Loving these longer films, and looking forward to the next instalment.

Very informative and cannot wait to see part 2! Great stuff Tod!

"Not even sure I should do this" I think that's in the top five things you never want to hear an engineer say.

Wonderful stuff Tod. I look forward to the next part.

16:02. Aaaaaaaaahhhh! Lovely job...I built one in high school from art and what little I could find from descriptions. My release was reinforced wood because I didn't have metal capabilities at that point. Man it was a blast to shoot.

Nice, commenting for algorithm. Good work Mr. Tod.

Thanks for sharing. I like how you explained everything matters.

Amazing Tod, thank you for sharing 😊

I was taught how to check the blade tension of my jeweler's saw the same way the romans checked the tensioning on their ropes. pluck it and if it sounds right you're good to go.

I would add a small rope coming up from the supporting bar to a series of eye bolts on the main shaft. This way you could easily get it back into neutral simply by pulling on the rope. If you have the end of hte rope somewhere near to the winch, you could do that right after shooting.

This was super cool and insightful, I can't wait for part 2!

Awesome video! I love the longer form videos where you explain how things work and are built and your methodology behind some of your design choices. Cheers! 💚

these machines are incredibly cool, thank you for sharing this. Nice work Tod

Tod I love seeing your introspection on this project you did years ago. This summer I finally built up a complicated folding bicycle I made over 20 years ago but never hung parts on to make it ride. Introspection to say the least!

super cool thank you .

Great stuff and so informative as well.

Thanks Tod, love these!

Fascinating! Loved it

Nice Job, Todd!

I can't wait to see how you pretension those bundles, I always wondered about that. Great video, lots of details I wasn't aware of like the scaling being expandable and relative to hole size.

Wow this is super!

Very cool.. very informative

I worked and build with wooden ships, masts, hoisting heavy stuff and other kinds of constructions that were mainly built by experience to be strong enough for the weirdest forces from all directions, and that teaches you an eye and feel for how big to build to be strong enough. It looks like the side frames where the buckling is showing might have gone worse due to greenwood setting/shrinking over time for a bit, giving most of the vertical force on the steel plates when shooting, but the main reason seems to be that the openings for the arms on the sideframes have reduced the strength of the sideframes too much and even cause a very heavy off center structural force, so much that the wood and steel on the thinnest frontal part start to bend towards horizontal and start to act like a hinge, therefor causing the buckling, the force of the tensioned ropes alone have the same effect of a load on a 4 legged table where 1 leg is removed, together with the rather thin middle frame around the hole for the arrow, that looks rather thin for such a heavy weighed construction that also has to bear the off center vertical loads and tahen from that indirect horizontal sectioned loads on the vertical side frames. As long as the front thinner part of the vertical sideframes is strong enough, there is no problem, but having the buckle now showing the too high load for the present frame, that will not get better at all with more tension on the ropes, the catapulta will collaps for sure, the extra holes drilled for the extra bolts only weakens the frames I'm afraid. Oak can withstand a lot of vertical load direct on the woodgrain, but combine it with sideloads and failure will happen for sure on such relative thin beams of the sideframes. I strongly advice to strengthen and save the catapulta with vertical steel cornerframes on the sideframes to save your wonderfull work.

Looking forward to seeing part 2.

You're a fantastic presenter, I'd love to see more of these long-form, multi episode topics

It's so interesting and exciting learning about this ancient engineerings. Roman's were indeed masters of building warfare apparatus. Love your efforts Tod.

Love it!

I'm hooked

Good stuff 👏

i love this, i hope you will test it against armour

OK, well I have definitely never seen this done before. Great video.

Awesome content, as always. Gotta admit though, I had a couple of serious 'that's what she said'-moments...

Wonderful video Todd and thank you for going into detail about these amazing weapons. I can't wait for part 2! I would like to get your take on my idea of using very long spikes, around 18 in / 45 cm, built in the form of a barrel style latch, to help assist you when you are increasing the tension of the headstock. These spikes could be mounted near the bottom of the framework in vertical positions, which would allow you to step onto the barrel latch "handle", so you can drive the spikes into the ground to help anchor it in position. This type of system might help keep the entire machine in place while when you are increasing the tension on the headstock. To retract the spikes, you could use the torque/spanner wrench to pry them up out of the ground, and then rotate the barrel latch "handle" a quarter turn to keep them in place. Of course you could use a hammer to drive the spikes into the ground as well, but the option of being able to step on them really would help a lot if you are planning surprise attacks on the enemy. A tiny piece of leather on the end of the winch keeper would also prevent the clanking sound as you draw the bow string. Just a few simple ideas that might have been used to assist the warriors of the ages. Lol. Keep up the fascinating work my friend. Cheers

Thanks' Tod for showing us it's features. 🤙🍻😸

You have a fantastic way of presenting things Todd. Great camera work (who ever is in charge of editing is top notch) and the way you explain things is clear even to those of us [cough]Myself[cough] that dont have a formal engineer's education. But you also go one step further and interact with the comments, answering questions and sharing ideas.

"I decided to just whack one out" I've just had my dinner, I don't need to see that! Oh... you mean the Catapulta. Ermm of course... ahem. please. continue... A great video and yes we love the details. :)

Can't wait to see part two! I've never seen one of these shot before, but it doesn't seem to have any sort of sighting system, which really makes me wonder if it can be made accurate enough to hit a target 600 yards away. This is great though, Tod.

I can’t wait for the next video!

this is fantastic

As an Italian, an engineer, and a hema practitioner, I must say: boy am I the demographic for thos film

Your videos are awesome dude genuinely enjoy and arguably more importantly learn from each and every one. Ty and please continue!

Yesss, another Tod's Video

As a currently certified first aid first responder and as a man of great faith, I give this a 9/10 safety rating and my personal blessing. youre welcome

It's like the golden ratio, but for catapultas. Keep it simple because it works.

When you tried to pull the buckled plate in there are wood shavings trapped behind it that would make it even more difficult. If you heated the plate where it buckled it may be possible to shrink it in place (keep water handy to prevent it catching fire).

I like big bolts and I cannot lie.

Amen!

best lad ever tod is.

Well done sir. Well done. The law of diminishing returns is a real thing. Same issue comes in when trying to launch a 🚀. You eventually reach a point where its weight becomes so much that you need more fuel, which adds more weight, which in turn means more fuel, which means more weight & so on till infinity. Hence why they are considering factories in space to get around the problem.

Whilst the book is out of print and about 300 USD to buy, there are digital copies that are very easy to find online.

M2. 50 cal of the ancient time, which just refuses to die.

16:00 brave move dude

Thank you for this fascinating walk down a kind of experimental archaeology! It's a joy to watch makers at their craft. I have a question about measuring the draw weight, however. The scale and associated ropes seem to take up maybe 10 inches of draw distance, which would very significantly affect the fealty of any readings. Am i correct in gathering that you were just demonstrating the change in pull after adjusting the main ropes and not measuring the draw weight of the device itself?

I'm curious about how much this entire device weighs. Do you have that handy? Thank you for doing these informative videos.

What an incredible machine you have there. 660 yards from a tension machine. Dang!

Cor blimey - torque about twistin' the Knight away . . . : )

Just saw the Polybolos; a catapulta that loads and shoots arrows endlesly; the first known machine-gun, basics like the catapulta, with camshaft and chaindrive. fascinating !

This really makes me want to build one. I abandoned a similar project about 20 years ago.

looking frwd to it

I am eagerly awaiting the anti armor tests.

Yay catapulta! 🙂

I think the extra drilled holes would probably weaken it.

Plastic rope? HERESY! 😁😁😁😁

I wonder if the speed of the last few inches of the string is high enough to give the arrow the extra last push you mentioned when I visualize in my head the mechanics during loose; the arch in the limbs is obviously intended to get a longer draw (thus arrowspeed and power) on the catapulta, (earlier versions with straight arms showed that loss of speed problem just as with the heavy shortdraw medieval crossbows), and the curve ads the recurve effect of higher speed of the bowstring during loose, the principle of the ropespring shows the highest push/power and speed mainly the first threequarter of the movement of the string and lims also due to the recurve-effect, the further forward the lims get, the lower the remaining springtension gets and thus slower combined with the straightening of the moving limb radius that reduces string speed as well, if I see that right, but correct me if I'm wrong.

Muito bom .

Best cliffhanger ever!

Ted, Might you decide to give your channel a new direction? Using the 6 simple engines, 32 complex engines, everything else you've done, survival skills ... make a series of "how to's" for Ukrainians. How to stay warm in winter without gas or electricity -- cook -- find or make shelter -- when is a bombed building maybe safe enough to live in one corner -- cleaning up the debris of war -- communicating -- disposing of human waste -- anything else you can think of that doesn't require electricity and petroleum. Romans and Greek civil engineers did it, Egyptians did it, Indians of Asia, many others. I was going to do this myself but found my skills just for a web page weren't up to it. Thanks for considering it.

"It's going to be kind of slow TV this one..." Nope, I could watch this stuff for hours!

The buckling could be from using green wood, but the center of the torsion bundles / bronze washers isn't also in the center of the wood at that cutout. So instead of mostly compression, there is an increased amount of bending force.

Could these things really shoot 660 yards? That's crazy, I would have expected about half of that distance.

A horseshoe reinforcement of iron bolted on those kinky sideplates of the headstock would greatly benefit your machine. Also 3 people for winding the bundles. Or that ground device for the headstock...

Todd , you are the guy to go to for most anything ancient and deadly and you’ve been that for a very long time too ! Cheers from California !🎃🎃🎃🎃🎃🎃